One look at Chris Hemsworth’s strikingly thin frame from shooting In the Heart of the Sea should tell you that making the historical maritime drama was no picnic. For filmmaker Ron Howard, his “origin story for Moby-Dick” proved to be one of the most daunting projects he’s ever been involved in.

“We did everything in this movie,” Howard told EW during a recent video interview in New York. “This movie was, for me as a director, at least as challenging as Apollo 13 — I’d say it was more. It was more challenging than Apollo 13 because of not only all the technical elements that we had to do, not only creating the whales, but lots and lots of scenes out in the real ocean.”

And while Howard may not identify as a landlubber, he’s not exactly a sea dog either.

“I don’t like the ocean,” the director admitted. “I don’t get seasick easily, [but] I do get seasick, I get sunburned. I don’t go out on the sea for fun. It’s not recreational for me out there. It’s a little frightening — and in a weird way, I think that’s part of what attracted me to this movie.”

Watch the video above for more from Howard, including how he and his team brought a 100-foot bull sperm whale to life on screen.